The broad objective of this project is an understanding of the basic metabolism of gastropod vectors of animal parasites as it relates to their biology and the biology of the intermediate stages of the parasites they harbor. Specific objectives include an elucidation of the physiological role of the newly discovered mannitol oxidase in gastropod mitochondria. This enzyme catalyzes the oxidation of mannitol to mannose in an oxygen-dependent reaction. Standard biochemical methodology will be used to purify and characterize mannitol oxidase, to examine the scope of its distribution in the invertebrates and to investigate the further metabolism of mannose in terms of the overall energy metabolism of gastropods.